One of the most common pieces of equipment for both household and work use is the ladder in its several embodiments: the extension ladder and the stepladder. Such ladders are used for tasks as diverse as painting, cleaning aluminum siding, cleaning gutters, changing lights and cleaning ceiling fans and stocking shelves. Since the work sites where such ladders are used are often irregular, uneven or sloping, care must be taken in properly setting up and deploying the ladders. Obviously placing a ladder on an uneven or irregular surface decreases the stability of the ladder; and this instability increases with the height or vertical extension of the ladder. Moreover, with the current issues of worker's compensation and personal injury liability, the improper deployment of a ladder by an employee can result in a physical injury for the employee and the possibility of legal damages and penalties against the employer for improper supervision of the work site.
Thus, in order to stabilize a ladder on an uneven or irregular surface the homeowner and employee resort to several common expedients. One expedient is to simply find a handy and available rock to wedge under the lowermost end of one of the side rails of the ladder to balance and level the ladder. Another expedient is to use shims, spacers or boards to level the ladder. However, in both cases the leveling is rough and approximate, and if the ladders needs repositioned, the leveling process must be undertaken anew. In addition, there is also an initial investment of time in searching for such spacers and levelers. And perhaps most importantly, such shims and spacers are not secured to the lower end of the ladder side rails, with the possibility of the ladder slipping off the shim or spacer with the individual falling off the ladder and sustaining serious injury.
The prior art discloses a wide variety of attachments and accessories for leveling and stabilizing ladders 9 on uneven and irregular terrain, surfaces and ground.
The Gilland patent (U.S. Pat. No. 3,414,082) discloses a ladder leveling apparatus that includes extensible mounting members that are pivotally attached to the side rails of the ladder.
The Hurwitz patent (U.S. Pat. No. 3,937,298) discloses a ladder leveling attachment that includes a transverse member attachable to the lower end of the ladder side rails, with the transverse member having opposed sockets for receiving therein adjustable legs for leveling the ladder.
The Larson et al. patent (U.S. Pat. No. 3,948,352) discloses a ladder leveler for extension ladders that includes a pair of sleeves each of which encompasses the lower end of the ladder side rails and is vertically adjustable and locks into place by a spring-biased pin.
The Fernandez patent (U.S. Pat. No. 4,143,742) discloses a ladder extension that includes a pair of l-shaped members that are bolted to each ladder side rail and are vertically adjustable along the lower portion of each side rail.
The Belt patent (U.S. Pat. No. 4,606,432) discloses an adjustable ladder leg that includes adjustable legs that are attached to each side rail by a clamping member and are slidably adjustable within channels that are also mounted to the clamping members.
The Huang patent (U.S. Pat. No. 4,671,383) discloses a ladder leveler that includes a pair of interconnected adaptors with each adaptor mounted to the bottom of each side rail, and an adjustable leg affixed to the underside of each adaptor for leveling the ladder.
The Katson et al. patent (U.S. Pat. No. 5,305,851) discloses an adjustable ladder leg for both a stepladder and an extension ladder.
The Dickerson et al. patent (U.S. Pat. No. 5,476,153) discloses a ladder leveling apparatus that includes a vertical support externally mounted to the lower end of each ladder side rail with each vertical support adjustable on the side rail and locked into place by a manually operable tightening member.
The Lovelady patent (U.S. Pat. No. 5,908,085) discloses a ladder leveling system that includes a pair of bands mounted to the lower end of each ladder rail for supporting a leg extension, and the leg extensions are interconnected for adjustment therealong by a spring loaded handle that extends between the ladder rails.
The McCrystal patent (U.S. Pat. No. 6,073,726) discloses an adjustable stepladder having adjustable legs and adjustable steps affixed to at least one pair of the side rails for leveling the ladder.
Nonetheless, despite the ingenuity of the above devices, there remains a need for a ladder leveling apparatus that is easily and quickly adjustable for leveling a ladder and is not cumbersome in use or weight when added to the ladder.